Accommodating intraocular lens

ABSTRACT

An accommodating intraocular lens to be implanted within the natural capsular bag of a human eye from which the natural lens matrix has been removed through an anterior capsulotomy in the bag circumferentially surrounded by a capsular remnant. During a postoperative healing period following surgery, the anterior capsular remnant fuses to the posterior capsule of the bag by fibrosis about haptics on the implanted lens, and the lens is deflected rearwardly to a distant vision position against the elastic posterior capsule of the bag in which the posterior capsule is stretched rearwardly. After fibrosis is complete, natural brain-induced contraction and relaxation of the ciliary muscle relaxes and stretches the fused remnant and increases and reduces vitreous pressure in the eye to effect vision accommodation by the fused remnant, the posterior capsule, and vitreous pressure. A method of utilizing the intraocular lens in a human eye to provide the eye with accommodation and to enable utilization of a lens with a relatively large optic.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of my application Ser. No.07/915,453, filed Jul. 16, 1992, now abandoned, which, in turn, is acontinuation-in-part of my application Ser. No. 07/515,636, filed Apr.27, 1990, now abandoned. Reference is also made to my application Ser.No. 07/744,472 filed Aug. 12, 1991.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to intraocular lenses and moreparticularly to novel accommodating intraocular lenses for implantationwithin the capsular bag of a human eye from which the natural lensmatrix has been removed by an extraction procedure which leaves intactwithin the eye the posterior capsule and an anterior capsule remnant ofthe natural lens. The invention relates also to a novel method ofutilizing the intraocular lenses in a human eye to provide the patientwith accommodation capability responsive to normal ciliary muscleaction.

2. Prior Art

The human eye has an anterior chamber between the cornea and the iris, aposterior chamber behind the iris containing a crystalline lens, avitreous chamber behind the lens containing vitreous humor, and a retinaat the rear of the vitreous chamber. The crystalline lens of a normalhuman eye has a lens capsule attached about its periphery to the ciliarymuscle of the eye by zonules and containing a crystalline lens matrix.This lens capsule has elastic optically clear anterior and posteriormembrane-like walls commonly referred by ophtalmologists as anterior andposterior capsules, respectively. Between the iris and ciliary muscle isan annular crevice-like space called the ciliary sulcus.

The human eye possesses natural accommodation capability. Naturalaccommodation involves relaxation and constriction of the ciliary muscleby the brain to provide the eye with near and distant vision. Thisciliary muscle action is automatic and shapes the natural crystallinelens to the appropriate optical configuration for focussing on theretina the light rays entering the eye from the scene being viewed.

The human eye is subject to a variety of disorders which degrade ortotally destroy the ability of the eye to function properly. One of themore common of these disorders involves progressive clouding of thenatural crystalline lens matrix resulting in the formation of what isreferred to as a cataract. It is now common practice to cure a cataractby surgically removing the cataractous human crystalline lens andimplanting an artificial intraocular lens in the eye to replace thenatural lens. The prior art is replete with a vast assortment ofintraocular lenses for this purpose. Examples of such lenses aredescribed in the following U.S. Pat. Nos.: 4,254,509, 4,298,996,4,409,691, 4,424,597, 4,573,998, 4,664,666, 4,673,406, 4,738,680,4,753,655, 4,778,463, 4,813,955, 4,840,627, 4,842,601, 4,963,148,4,994,082, 5,047,051.

As is evident from the above patents, intraocular lenses differ widelyin their physical appearance and arrangement. This invention isconcerned with intraocular lenses of the kind having a central opticalregion or optic and haptics which extend outward from the optic andengage the interior of the eye in such a way as to support the optic onthe axis of the eye. My above-listed U.S. Pat. No. 5,047,051, which wasfiled concurrently with my earlier mentioned application Ser. No.07/515,636, discloses an intraocular lens having a haptic anchor plate,an optic at the longitudinal center of the plate, and resilient hapticloops staked to the ends of the plate.

Up until the late 1980's, cataracts were surgically removed by eitherintracapsular extraction involving removal of the entire human lensincluding both its outer lens capsule and its inner crystalline lensmatrix, or by extracapsular extraction involving removal of the anteriorcapsule of the lens and the inner crystalline lens matrix but leavingintact the posterior capsule of the lens. Such intracapsular andextracapsular procedures are prone to certain post-operativecomplications which introduce undesirable risks into their utilization.Among the most serious of these complications are opacification of theposterior capsule following extracapsular lens extraction, intraocularlens decentration, cystoid macular edema, retinal detachment, andastigmatism.

Starting in the late 1980's, an improved surgical procedure calledcapsulorhexis (a form of anterior capsulotomy) was developed toalleviate or avoid the above and other post-operative complications andrisks involved in intracapsular and extracapsular cataract extraction.Simply stated, capsulotomy involves forming an opening in the anteriorcapsule of the natural lens, leaving intact within the eye a capsularbag having an elastic posterior capsule, an anterior capsular remnantabout the anterior capsulotomy, and an annular sulcus, referred toherein as a capsular bag sulcus, between the anterior capsule remnantand the outer circumference of the posterior capsule. This capsular bagremains attached about its periphery to the surrounding ciliary muscleof the eye by the zonules of the eye. The cataractous natural lensmatrix is extracted from the capsular bag through the anteriorcapsulotomy by phacoemulsification and aspiration or in some other wayafter which an intraocular lens is implanted within the bag through thecapsulotomy.

The type of anterior capsulotomy known as capsulorhexis involves acontinuous tear circular or round capsulotomy, tearing the anteriorcapsule of the natural lens capsule along a generally circular tear linesubstantially coaxial with the lens axis and removing the generallycircular portion of the anterior capsule surrounded by the tear line. Acontinuous tear circular capsulorhexis, if performed properly, providesa generally circular capsulotomy through the anterior capsule of thenatural lens capsule substantially coaxial with the axis of the eye andsurrounded circumferentially by a continuous annular remnant or rim ofthe anterior capsule having a relatively smooth and continuous inneredge bounding the capsulotomy. During a continuous tear circularcapsulorhexis, however, the anterior rim is often accidentally torn orsliced radially or otherwise ruptured, or the inner rim edge is nickedor sliced in a manner which renders the rim prone to tearing radiallywhen the rim is stressed, as it is during fibrosis as discussed below.

Another capsulorhexis procedure, referred to as an envelopecapsulorhexis, involves cutting a horizontal incision in the anteriorcapsule of the natural lens capsule, then cutting two vertical incisionsin the anterior capsule intersecting and rising from the horizontalincision, and finally tearing the anterior capsule along a tear linehaving an upper upwardly arching portion which starts at the upperextremity of the vertical incision and continues in a downward verticalportion parallel to the vertical incision which extends downwardly andthen across the second vertical incision. This procedure produces in theanterior capsule a generally archway-shaped envelope capsulotomycentered on the axis of the eye. The capsulotomy is bounded at itsbottom by the horizontal incision, at one vertical side by the verticalincision, at its opposite vertical side by the second vertical incisionof the anterior capsule, and at its upper side by the upper archingportion of the capsule tear. The vertical incision and the adjacent endof the horizontal incision form a flexible flap at one side of thecapsulotomy. The vertical tear edge and the adjacent end of thehorizontal incision form a second flap at the opposite side of thecapsulotomy.

Yet another capsulorhexis procedure, referred to as a beer can or canopener capsulorhexis, involves piercing the anterior capsule of thenatural lens capsule at a multiplicity of intersecting positions along acircular line substantially coaxial with the axis of the eye and thenremoving the generally circular portion of the capsule circumferentiallysurrounded by the line. This procedure produces a generally circularcapsulotomy substantially coaxial with the axis of the eye and boundedcircumferentially by an annular remnant or rim of the anterior capsule.The inner edge of this rim has a multiplicity of scallops formed by theedges of the pierced holes in the anterior capsule which render theannular remnant or rim prone to tearing radially when the rim isstressed, as it is during fibrosis as discussed below.

Intraocular lenses also differ with respect to their accommodationcapability, and their placement in the eye. Accommodation is the abilityof an intraocular lens to accommodate, that is to focus the eye for nearand distant vision. My application Ser. No. 07/744,472 and some of theearlier listed patents describe accommodating intraocular lenses. Othersof the listed patents describe non-accommodating intraocular lenses.Most non-accommodating lenses have single focus optics which focus theeye at a certain fixed distance only and require the wearing of eyeglasses to change the focus. Other non-accommodating lenses have bifocaloptics which image both near and distant objects on the retina of theeye. The brain selects the appropriate image and suppresses the otherimage, so that a bifocal intraocular lens provides both near vision anddistant vision sight without eyeglasses. Bifocal intraocular lenses,however, suffer from the disadvantage that each bifocal image representsonly about 40% of the available light and the remaining 20% of the lightis lost in scatter.

There are four possible placements of an intraocular lens within theeye. These are (a) in the anterior chamber, (b) in the posteriorchamber, (c) in the capsular bag, and (d) in the vitreous chamber. Theintraocular lens disclosed in my application Ser. No. 07/744,472 isintended for placement within the capsular bag.

SUMMARY OF THE INVENTION

According to one of its aspects, this invention provides improved platehaptic accommodating intraocular lenses to be implanted within thecapsular bag of a human eye which remains in the eye after removal ofthe natural matrix from the human lens capsule through an anteriorcapsulotomy produced by a capsulorhexis procedure. An improvedaccommodating intraocular lens according to the invention has a centraloptic and two plate haptics which extend generally radially outward fromdiametrically opposite sides of the optic and are movable anteriorly andposteriorly relative to the optic. The width of the plate optics issubstantially the same as the diameter of the optic. In some describedlens embodiments, the plate haptics are relatively stiff, their innerends are hinged to the optic, and the anterior/posterior movement Of thehaptics involves pivotal movement of the haptics at their hinges. Inother described embodiments, the plate haptics are resiliently flexible,and the anterior/posterior movement of the haptics relative to the opticinvolves resilient flexing or bending of the haptics throughout theirlength. In this regard, it is important to note that the terms "flex","flexing", "flexible", and the like are used herein in a broad sense tocover both hinged and resiliently bendable haptics. According to anembodiment of the invention, the lens body is constructed of a materialhaving an elastic memory, and the lens body has an unstressedconfiguration in which the haptics, optic and hinge means are disposedsubstantially in a common plane.

Certain of the described lens embodiments, referred to as simple platehaptic lenses, are intended for use when the capsularhexis procedureutilized in cataract surgery is a properly performed continuous tearcircular capsulotomy, which provides an anterior capsulotomycircumferentially surrounded by an anterior capsule remnant in the formof an intact, circumferentially continuous annular rim that remains freeof splits and tears throughout fibrosis following surgery. A simpleplate haptic lens of the invention is implanted within the eye in aposition wherein the lens optic is aligned on the axis of the eye withthe anterior capsulotomy and the outer ends of the plate haptics aresituated within the capsular bag sulcus in contact with the sulcus wall.The normally posterior side of the lens then faces the elastic posteriorcapsule of the bag.

During a post operative healing period on the order of three weeks,active endodermal cells on the posterior side of the anterior capsularrim cause fusion of the rim to the elastic posterior capsule byfibrosis. Fibrosis occurs about the haptics in such a way that thehaptics are effectively "shrink-wrapped" by the capsular bag and formradial pockets between the anterior rim and the posterior capsule. Thesepockets contain the haptics and act to position and center the lens inthe eye. The anterior capsular rim shrinks during fibrosis. Thisshrinkage combined with shrink-wrapping of the haptics causes endwisecompression of the lens in a manner which tends to deflect the center ofthe lens along the axis of the eye relative to the fixated outer hapticends. The intact fibrosed capsular rim prevents forward deflection ofthe lens, so that fibrosis-induced deflection of the lens occursrearwardly to a position in which the lens presses against the elasticposterior capsule and stretches this capsule rearwardly.

In order to insure proper formation of the haptic pockets duringfibrosis, brain-induced flexing of the lens during fibrosis is preventedby using a ciliary muscle relaxant, such as Atropine drops, to maintainthe ciliary muscle in a relaxed state and/or using a suture tophysically prevent flexing of the lens. In the Atropine-induced relaxedstate of the ciliary muscle, the capsular bag is stretched to itsmaximum diameter. The anterior capsular rim is then stretched to a tauttrampoline-like condition or position in which the rim prevents forwardflexing of lens from its posterior position against the posteriorcapsule. The rim undergoes fibrosis from this taut condition orposition.

Use of the ciliary muscle relaxant is discontinued upon completion offibrosis. Thereafter, when the brain activates the ciliary muscle to itsnatural relaxed state, the capsular bag and the fibrosed anteriorcapsular rim are stretched, the rim to its taut trampoline-likecondition in which the rim deflects the lens rearwardly to and holds thelens in its posterior position. In this position of the lens, which isits distant vision position, it presses rearwardly against and stretchesthe elastic posterior capsule. The stretched posterior capsule thenexert a forward bias force on the lens.

The plate haptic lenses of the invention are uniquely constructed andarranged to utilize the fibrosed anterior capsular rim, the elasticposterior capsule, the vitreous cavity pressure, and the naturalbrain-controlled ciliary muscle action of the eye to providepostoperative accommodation for near vision. Thus, when looking at anear object, the brain constricts the ciliary muscle. This relaxes thefibrosed anterior rim, increases vitreous cavity pressure, andcompresses the lens endwise in such a way as to effect forwarddeflection, i.e. accommodation movement, of the lens optic along theaxis of the eye to a near vision position. Depending upon the amount ofaccommodation, accommodation deflection of the lens is producedinitially by the increase in viteous pressure and the forward bias forceof the stretched posterior capsule and finally by forward buckling ofthe lens in response to endwise compression of the lens. Subsequentbrain-activated relaxation of the ciliary muscle stretches the capsularbag and the fibrosed anterior capsular rim to return the lens rearwardlytoward its distant vision position.

A plate haptic lens according to the invention may have a normalunstressed configuration, such that when deflected from this normalunstressed configuration, the lens develops internal elastic strainenergy forces which bias the lens toward its normal unstressedconfiguration in a manner which aids accommodation. The lens may begenerally flat, anteriorly arched, or posteriorly arched in this normalunstressed configuration. One disclosed embodiment of the lens includesauxiliary springs for aiding lens accommodation. Some disclosed lensembodiments have integral fixation means at the haptic ends around whichfibrosis of the anterior rim of the capsular bag occurs to fix the lensagainst dislocation in the eye. Other disclosed embodiments havefixation elements from which the lens proper is separable to permitlater removal of the lens for repair or correction and replacement ofthe lens in its exact original position within the eye.

The simple plate haptic lenses discussed above are intended for use whenthe capsulorhexis procedure performed on the eye provides an anteriorcapsular remnant or rim that remains intact and circumferentiallycontinuous throughout fibrosis. According to another of its aspects,this invention provides modified accommodating intraocular lenses,referred to as plate haptic spring intraocular lenses, for use when theanterior capsular remnant or rim of the capsular bag is ruptured, thatis cut or torn. A ruptured capsular rim may be produced in differentways. For example, improper performance of a continous tear circularcapsulorhexis may result in accidental cutting or tearing of theanterior rim. A beer can or can opener capsulorhexis, on the other hand,produces an anterior capsular rim which is not intact and has an innerscalloped edge having stress-inducing regions that render the rim veryprone to tearing during surgery or subsequent fibrosis. An envelopecapsulorhexis inherently produces an anterior capsular remnant which isruptured and not intact.

A ruptured anterior capsular remnant or rim may preclude utilization ofa simple plate haptic lens of the invention for the following reasons. Aruptured rim may not firmly retain the lens haptics in the sulcus of thecapsular bag during fibrosis, thereby rendering the lens prone todecentration and/or posterior or anterior dislocation. A rupturedcapsular rim may be incapable of assuming the taut trampoline-likecondition of a non-ruptured rim. If so, a ruptured capsular rim isincapable of effecting full posterior deflection of a plate haptic lensto a distant viewing position against the posterior capsule during andafter fibrosis. In fact, a ruptured capsular rim may permit anteriordeflection of the lens. In either case, since the power of the lens isselected for each individual patient and is dependent upon theirspectacle power, and since good vision without glasses requires the lensoptic to be at precisely the correct distance from the retina, a simpleplate haptic lens of the invention may not be acceptable for use with aruptured anterior capsular remnant or rim.

The accommodating plate haptic spring lenses of the invention aredesigned for use when the anterior capsular remnant or rim of thecapsular bag is ruptured. These plate haptic spring lenses are similarto the simple plate haptic lenses but have resilient springs, such asspring loops, at the ends of the plate haptics. When a plate hapticspring lens is implanted in a capsular bag, the haptic springs pressoutward against the wall of the capsular bag sulcus to fixate the lensin the bag during fibrosis. Fibrosis occurs about the springs in such away as to effect fusion of the ruptured anterior remnant to theposterior capsule, firm fixation of the the springs and hence thehaptics in the bag, and posterior deflection of the lenses against theelastic posterior capsule during fibrosis. Brain-induced constrictionand relaxation of the ciliary muscle after fibrosis with a rupturedcapsular rim effects accommodation of the plate haptic spring lens inmuch the same way as occurs with the simple plate haptic lens and anintact non-ruptured capsular rim.

While the plate haptic spring lenses of the invention are designed foruse with a ruptured anterior capsular remnant or rim, these lenses canalso be utilized with an intact rim. A plate haptic spring lens alsocompensates for improper lens placement in the eye with one end of thelens situated in the capsular bag and the other end of the lens situatedin the ciliary sulcus of the eye. In this regard, an advantage of theplate haptic spring lenses of the invention over the simple plate hapticlenses resides in the fact that the spring lenses eliminate the need tohave on hand in the operating room both a simple plate haptic lens foruse with an intact capsular rim and a plate haptic spring lens as asubstitute for the plate haptic lens in the event the rim is rupturedduring surgery.

Another advantage of the plate haptic spring lenses over the simpleplate haptic lenses of the invention resides in the fact that the hapticspring lenses permit an optic of larger diameter than those of simpleplate haptic lenses whose optic diameters will normally be restricted tothe range of 4-7 mm. Thus, the haptic spring lenses rely on the hapticsprings rather than the capsular remnant or rim to retain the lenses inposition during fibrosis. As a consequence, these lenses may be usedwith a capsular remnant or rim of reduced radial width or a capsular rimwhich is slit or torn, both of which rim types provide a capsulotomy oflarger effective size than those possible with a simple plate hapticlens. A larger capsulotomy, in turn, permits a larger optic diameterwhich offers certain opthalmological benefits. According to one aspectof this invention, such a large capsulotomy is provided after fibrosisis complete by using a laser to slit the anterior capsular rim radiallyor cut the rim circumferentially to enlarge the capsulotomy.

A further aspect of the invention concerns a novel method of utilizingan accommodating lens of the invention to provide accommodation in ahuman eye whose natural lens matrix has been removed from the lenscapsule by a procedure involving capulorhexis of the anterior capsule ofthe natural lens. The method may be utilized to replace a natural lensfrom which a cataract has been removed and to correct a refractive errorin the eye of a patient who previously wore glasses in order to enablethe patient to see well without glasses. For example, the invention cancan be utilized to correct refractive errors and restore accommodationto persons in their mid-40's who require reading glasses or bifocals fornear vision by replacing the clear non-cataractous crystalline lensmatrix of their eyes with an accomodating intraocular lens according tothe invention. According to the method of utilizing a plate hapticspring lens of the invention, the anterior capsular remnant or rim ofthe capsular bag is slit radially or cut to enlarge the anteriorcapsulotomy after capsulorhexis is complete to permit the use of a lenswith a relatively large diameter optic larger than 6 or 7 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section through a human eye from which the natural lensmatrix has been removed by a surgical procedure involving capsulorhexisof the natural lens, and illustrating an accommodating simple platehaptic accommodating lens according to this invention implanted withinthe capsular bag of the eye;

FIG. 1A is a section through a normal human eye;

FIG. 2 is an anterior side view of the intraocular lens of FIG. 1;

FIG. 3 is a section taken on line 3--3 in FIG. 2;

FIG. 4 is a section taken on line 4--4 in FIG. 1;

FIGS. 5-8 illustrate the manner in which the intraocular lens of FIGS.1-4 is utilized in the eye of FIG. 1 to provide accommodation;

FIGS. 9-12 are sections, similar to FIG. 3, through modifiedaccommodating intraocular lenses according to the invention havingalternative optical shapes;

FIG. 13 is a section similar to FIG. 3 through a modified accommodatingintraocular lens according to the invention illustrating the lens in itsnormal unstressed configuration;

FIG. 14 is a section similar to FIG. 13, illustrating the lens in itsdistant vision position;

FIG. 15 is a section through a modified accommodating intraocular lensaccording to the invention having an anteriorly displaced optic;

FIG. 16 is an anterior side view of a modified accommodating intraocularlens according to the invention having integral fixation means forfixing the lens in the capsular bag of the eye;

FIG. 17 is a section taken on line 17--17 in FIG. 16;

FIGS. 18-21 are anterior side views of modified accommodatingintraocular lenses according to the invention having alternativeintegral fixation means for fixing the lenses in the capsular bag of theeye;

FIG. 22 is an anterior side view of a modified accommodating intraocularlens according to the invention having springs for aiding accommodation;

FIG. 23 illustrates the lens of FIG. 22 implanted within the capsularbag of a human eye like that in FIG. 1, and showing the lens in theposition which the lens occupies immediately after surgery as well asafter a certain degree of accommodation;

FIG. 24 is a view similar to FIG. 23 showing the lens in its posteriordistant vision position;

FIGS. 25-30 are anterior side views of modified accommodatingintraocular lenses according to the invention having separate fixationmeans for fixing the lenses in the capsular bag of a human eye like thatin FIG. 1;

FIGS. 31-34 illustrate modified accommodating intraocular lensesaccording to the invention having integral fixation means;

FIGS. 35-37 illustrate the capsulotomy produced by a continuous tearcircular capsulotomy, a beer can capsulotomy, and an envelopecapsulotomy, respectively;

FIG. 38 is an anterior face view of a plate haptic spring lens accordingto the invention;

FIG. 39 is a view similar to FIG. 4 showing the plate haptic spring lensof FIG. 38 implanted within the eye;

FIG. 40 is an enlarged section taken on line 40--40 in FIG. 39;

FIGS. 41 and 42 illustrate two ways of enlarging the capsulotomy of acapsular bag after completion of fibrosis to allow anterior movement ofa relatively large lens optic;

FIG. 43 is an anterior side view of a modified plate haptic lensaccording to the invention; and

FIGS. 44-46 illustrate modified plate haptic spring lenses according tothe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to these drawings and first to FIGS. 1 and 1A, there isillustrated a human eye 10 from which the natural crystalline lensmatrix was previously removed by a surgical procedure involvingcontinous tear circular capsulorhexis of the natural lens L of the eye.The natural lens comprises a lens capsule having elastic anterior andposterior walls A and P, respectively, which are referred to byophthalmologists and herein as anterior and posterior capsules,respectively. Within the lens capsule is a normally optically clearcrystalline lens matrix M. In many individuals, this lens matrix becomescloudy with advancing age and froms what is called a cataract. It is nowcommon practice to restore a cataract patient's vision by removing thecataract from the natural lens and replacing the lens matrix by anartificial intraocular lens.

As mentioned earlier, continous tear circular capsulorhexis involvestearing the anterior capsule A along a generally circular tear line insuch a way as to form a relatively smooth-edged circular opening orcapsulotomy in the center of the anterior capsule. The cataract isremoved from the natural lens capsule through this capsulotomy. Aftercompletion of this surgical procedure, the eye includes an opticallyclear anterior cornea 12, an opaque sclera 14 on the inner side of whichis the retina 16 of the eye, an iris 18, a capsular bag 20 behind theiris, and a vitreous cavity 21 behind the capsular bag filled with thegel-like vitreous humor. The capsular bag 20 is the structure of thenatural lens of the eye which remains intact within the eye after thecontinous tear circular tear capsulorhexis has been performed and thenatural lens matrix has been removed from on the natural lens.

The capsular bag 20 includes an annular anterior capsular remnant or rim22 and an elastic posterior capsule 24 which are joined along theperimeter of the bag to form an annular crevice-like capsular bag sulcus25 between rim and posterior capsule. The capsular rim 22 is the remnantof the anterior capsule of the natural lens which remains aftercapsulorhexis has been performed on the natural lens. This rimcircumferentially surrounds a central, generally round anterior opening26 (capsulotomy) in the capsular bag through which the natural lensmatrix was previously removed from the natural lens. The capsular bag 20is secured about its perimeter to the ciliary muscle of the eye byzonules 30.

Natural accommodation in a normal human eye having a normal humancrystalline lens involves automatic contraction or constriction andrelaxation of the ciliary muscle of the eye by the brain in response tolooking at objects at different distances. Ciliary muscle relaxation,which is the normal state of the muscle, shapes the human crystallinelens for distant vision. Ciliary muscle contraction shapes the humancrystalline lens for near vision. The brain-induced change from distantvision to near vision is referred to as accommodation.

Implanted within the capsular bag 20 of the eye 10 is an accommodatingintraocular lens 32 according to this invention which replaces andperforms the accommodation function of the removed human crystallinelens. Lens 32 is referred to in places as a simple plate haptic lens todistinguish it from the lager described plate haptic spring lens of theinvention. As mentioned earlier and will become readily understood asthe description proceeds, the accommodating intraocular lens may beutilized to replace either a natural lens which is virtually totallydefective, such as a cataractous natural lens, or a natural lens thatprovides satisfactory vision at one distance without the wearing ofglasses but provides satisfactory vision at another distance only whenglasses are worn. For example, the accommodating intraocular lens of theinvention can be utilized to correct refractive errors and restoreaccommodation for persons in their mid-40's who require reading glassesor bifocals for near vision.

Intraocular lens 32 comprises a body 33 which may be formed ofrelatively hard material, relatively soft flexible semi-rigid material,or a combination of both hard and soft materials. Examples of relativelyhard materials which are suitable for the lens body are methylmethacrylate, polysulfones, and other relatively hard biologically inertoptical materials. Examples of suitable relatively soft materials forthe lens body are silicone, hydrogels, thermolabile materials, and otherflexible semi-rigid biologically inert optical materials.

The lens body 33 has a generally rectangular shape and includes acentral optical zone or optic 34 and plate haptics 36 extending fromdiametrically opposite edges of the optic. The haptics have inner endsjoined to the optic and opposite outer free ends. The haptics 36 aremovable anteriorly and posteriorly relative to the optic 34, that is tosay the outer ends of the haptics are movable anteriorly and posteriorlyrelative to the optic. The particular lens embodiment illustrated isconstructed of a resilient semi-rigid material and has flexible hinges38 which join the inner ends of the haptics to the optic. The hapticsare relatively rigid and are flexible about the hinges anteriorly andposteriorly relative to the optic. These hinges are formed by grooves 40which enter the anterior side of the lens body and extend along theinner ends of the haptics. The haptics 36 are flexible about the hinges38 in the anterior and posterior directions of the optic. The lens has arelatively flat unstressed configuration, illustrated in FIGS. 2 and 3,wherein the haptics 36 and their hinges 38 are disposed in a commonplane transverse to the optic axis of the optic 34. Deformation of thelens from this unstressed configuration by anterior or posteriordeflection of the haptics about their hinges 38 creates in the hingeselastic strain energy forces which bias the lens to its unstressedconfiguration. If the lens is constructed of a relatively hard opticmaterial, it may be necessary to replace the flexible hinges 38 bypivotal hinges of some kind. In a later described lens embodiment of theinvention, the haptic hinges are eliminated, and the haptics are madeflexible throughout their length.

The accommodating intraocular lens 32 is implanted within the capsularbag 20 of the eye 10 in the position shown in FIGS. 1 and 5. Whenimplanting the lens in the bag, the ciliary muscle 28 of the eye ismaintained in a relaxed state in which the muscle stretches the capsularbag 20 to its maximum diameter. The lens is inserted into the bagthrough the anterior capsular capsulotomy 26 and placed in the positionshown in FIGS. 1 and 4. In this position, the lens optic 34 is alignedon the axis of the eye with the capsolotomy, the posterior side of thelens faces the elastic posterior capsule 24 of the bag, and the outerends of the lens haptics 36 are situated within the sulcus 25 at theradially outer perimeter of the bag. The overall length of the lenssubstantially equals the inner diameter (10-11 mm) of the stretchedcapsular bag so that the lens fits snugly within the stretched capsularbag, as shown. This prevents decentration of the lens and therebypermits the optic 34 to be smaller such that it can move forward insidethe capsular rim during the later described accommodation.

During a post-operative healing period on the order of two to threeweeks following surgical implantation of the lens 32 in the capsular bag20, epithelial cells under the anterior capsular rim 22 of the bag causefusion of the rim to the posterior capsule 24 by fibrosis. This fibrosisoccurs around the lens haptics 36 in such a way that the haptics are"shrink-wrapped" by the capsular bag 20, and the haptics form pockets 42in the fibrosed material F (FIGS. 4 and 6-8). These pockets position andcenter the lens in the eye. In order to insure proper formation of thehaptic pockets 42, sufficient time must be allowed for fibrosis to occurto completion without flexing of the lens haptics 36 by ciliary muscleaction. One way of accomplishing this is to have the patientperiodically administer cycloplegic drops, such as Atropine, into hiseye during the post-operative fibrosis period. These drops maintain theciliary muscle 28 in its relaxed state. In this relaxed state, thecapsular bag 20 is stretched to its maximum diameter, and the anteriorcapsular rim 22 is stretched to a taut trampoline-like condition orposition. The rim fibroses from this taut condition.

The capsular rim 22 shrinks during fibrosis and thereby shrinks thecapsular bag 20 slightly in its radial direction. This shrinkagecombined with shrink wrapping of the lens haptics 36 produces opposingendwise compression forces on the ends of the haptics which tend tobuckle or flex the lens at its hinges 38 and thereby move the lens optic34 along the axis of the eye. Unless restrained, this flexing of thelens might occur either forwardly or rearwardly. The taut anteriorcapsular rim 22 pushes rearwardly against and thereby prevents forwardflexing of the lens. Accordingly, endwise compression of the lens duringfibrosis aided by the rearward thrust of the taut capsular rim againstthe lens haptics 36 causes rearward flexing of the lens from its initialposition of FIGS. 1 and 5 to is position of FIG. 6. The lens haptics 36are made sufficiently rigid that they will not be bent or bowed by theforces of fibrosis. At the conclusion of fibrosis, the lens occupies itsposterior position of FIG. 6 wherein the lens presses rearwardly againstthe elastic posterior capsule 24 and stretches this capsule rearwardly.The posterior capsule then exerts a forward elastic bias force on thelens. This posterior position of the lens is its distant visionposition.

Another way of preventing ciliary muscle induced flexing of the lens 32during fibrosis is to place sutures within the hinge grooves 40. Removalof these sutures after completion of fibrosis may be accomplished byusing sutures that are either absorbable in the fluid within the eye orby using sutures made of a material, such as nylon, which can be removedby a laser.

Natural accommodation in a normal human eye involves shaping of thenatural crystalline lens by automatic contraction and relaxation of theciliary muscle of the eye by the brain to focus the eye at differentdistances. Ciliary muscle relaxation shapes the natural lens for distantvision. Ciliary muscle contraction shapes the natural lens for nearvision.

The accommodating intraocular lens 32 is uniquely constructed to utilizethis same ciliary muscle action, the fibrosed capsular rim 22, theelastic posterior capsule 24, and the vitreous pressure within thevitreous cavity 21 to effect accommodation movement of the lens optic 34along the optic axis of the eye between its distant vision position ofFIG. 6 to its near vision position of FIG. 8. Thus, when looking at adistant scene, the brain relaxes the ciliary muscles 28. Relaxation ofthe ciliary muscle stretches the capsular bag 20 to its maximum diameterand its fibrosed anterior rim 22 to the taut trampoline-like conditionor position discussed above. The taut rim deflects the lens rearwardlyto its posterior distant vision position of FIG. 6 in which the elasticposterior capsule 24 is stretched rearwardly by the lens and therebyexerts a forward bias force on the lens. When looking at a near scene,such as a book when reading, the brain constricts or contracts theciliary muscle. This ciliary muscle contraction has the three-foldeffect of increasing the vitreous cavity pressure, relaxing the capsularbag 20 and particularly its fibrosed capsular rim 22, and exertingopposing endwise compression forces on the ends of the lens haptics 36with resultant endwise compression of the lens. Relaxation of thecapsular rim permits the rim to flea forwardly and thereby enables thecombined forward bias force exerted on the lens by the rearwardlystretched posterior capsule and the increased vitreous cavity pressureto push the lens forwardly in an initial accommodation movement from theposition of FIG. 6 to the intermediate accommodation position of FIG. 7.

In this intermediate accommodation position, the lens is substantiallyflat, and the ends of the lens haptics and their hinges 38 are disposedsubstantially in a common plane normal to the axis of the eye. Duringthe initial accommodation, the lens arches rearwardly so that endwisecompression of the lens by ciliary muscle contraction produces arearward buckling force on the lens which resists the initialaccommodation. However, the increased vitreous cavity pressure and theforward bias force of the stretched posterior capsule are sufficient toovercome this opposing rearward buckling force and effect forwardaccommodation movement of the lens to and at least just slightly beyondthe intermediate position of FIG. 7. At this point, endwise compressionof the lens by the contracted ciliary muscle produces a forward bucklingforce on the lens which effects final accommodation of the lens beyondthe intermediate position of FIG. 7 to the near vision position of FIG.8. Subsequent brain-induced relaxation of the ciliary muscle 28 inresonse to looking at a distant scene reduces the vitreous cavitypressure, stretches the capsular bag 20 to its maximum diameter, andrestores the anterior capsular rim 22 to its taut trampoline-likecondition to effect return of the lens to its distant viewing positionof FIG. 6. During accommodation, the lens optic 34 moves along the axisof the eye toward and away from the retina 16. The power of the optic isselected by the brain to sharply focus incoming light rays on the retinathroughout the range of this accommodation movement.

The lens haptics 36 flex at their hinges 38 with respect to the lensoptic 34 during accommodation. Any elastic strain energy forcesdeveloped in the hinges during this flexing produces additional anteriorand/or posterior forces on the lens. For example, assume that the lensis relatively flat, i.e. if the lens haptics 36 lie in a common plane asshown in FIG. 1, in the normal unstressed state of the lens. In thiscase, posterior deflection of the lens from its position of FIG. 1 toits distant vision position of FIG. 6 creates elastic strain energyforces in the hinges 38 which urge the lens forwardly back to itsunstressed position of FIG. 1 and thus aid the above discussed initialaccommodation of the lens in response to contraction of the ciliarymuscle. Final accommodation flexing of the lens from its intermediateposition of FIG. 7 to its near vision position of FIG. 8 creates elasticstrain energy forces in the hinges 38 which urge the lens rearwardlytoward its unstressed position and thus aid initial return of the lensfrom its near vision position to its distant vision position in responseto relaxation of the ciliary muscle. The lens may be designed to assumesome other normal unstressed position, of course, in which case anyelastic strain energy forces created in the lens during flexing of thehaptics will aid, resist, or both aid and resist accommodation of thelens to its near vision position and return of the lens to its distantvision position depending upon the unstressed position of the lens.

During accommodation the lens haptics 36 slide endwise in their fibrosedtissue pockets 42. As shown best in FIGS. 2 and 3, the haptics aretapered endwise in width and thickness to enable the haptics to movefreely in the pockets. The lens optic 34 moves toward and away from theanterior capsular rim 22. The diameter of the optic is made as large aspossible to maximize its optical imaging efficiency. The optic ispreferably but not necessarily made smaller than the diameter of thecapsulotomy 26 to permit accommodation movement of the optic into andfrom the capsulotomy without interference by the capsular rim 22 inorder to maximize the accommodation range. The actual lens dimensionsare determined by each patient's ocular dimensions. The dimensions of asimple plate haptic intraocular lens according to the invention willgenerally fall within the following ranges:

    ______________________________________                                        Optic diameter: 3.0 mm-7.0 mm                                                 Overall lens length:                                                                           9.0 mm-11.5 mm                                               Haptic thickness:                                                                             0.25 mm-0.35 mm                                               ______________________________________                                    

Refer now to FIGS. 9-15 illustrating several possible alternative shapesof the accommodating intraocular lens. The modified lens 50 illustratedin FIG. 9 is identical to lens 32 of FIGS. 1-8 except that the haptichinges 38 of lens 32 are eliminated in the lens 50, and the haptics 52of the lens 50 are flexible throughout their length, as illustrated bythe broken lines in FIG. 9. The modified lens 54 in FIG. 10 has ananteriorly arched unstressed shape and includes a bi-convex optic 56,flexible hinges 58, and anteriorly vaulted haptics 60 with convexanterior surfaces 62. The convex anterior face 64 of the optic 56 andthe convex anterior haptic surfaces 62 are rounded to a common radius.The modified intraocular lens 66 in FIG. 11 is relatively flat andincludes an optic 68 having a planar Fresnel anterior face 70 and aconvex posterior face 72, haptics 73, and flexible haptic hinges 74. Themodified lens 76 in FIG. 12 has a posteriorly arched unstressed shapeand includes an optic 78 having a planar anterior face 80 and a convexposterior face 82, haptics 84 having convex posterior surfaces 86 andhaptic hinges 88. The posterior face 82 of the optic 78 and theposterior surfaces 86 of the haptics 84 are rounded to a common radius.The modified lens 90 illustrated in FIGS. 13 and 14 includes an optic 92and flexible haptics 94 and has an unstressed near vision configurationshown in FIG. 13. The haptics flex to permit posterior deflection of thelens to its distant vision configuration of FIG. 14. The optic 92 isposteriorly offset relative to the inner ends of the haptics to permitgreater anterior displacement of the optic during accommodation withoutcontacting the anterior capsular rim 22 of the capsular bag 20. Themodified intraocular lens 100 of FIG. 15 includes haptics 102 and anoptic 104 which is offset anteriorly relative to the inner ends of thehaptics. The haptics are joined to diametrically opposite sides of theoptic by flexible hinges 106.

The modified intraocular lenses of FIGS. 9-15 are implanted within thecapsular bag 20 of the eye 10 and utilize the posterior bias of thefibrosed capsular rim 22, the posterior capsule 24, changes in vitreouscavity pressure, and the patient's ciliary muscle action to effectaccommodation in the same manner as described in connection with theintraocular lens 32 of FIGS. 1-8. In the case of the lens 100 in FIG.15, the outer ends of its haptics 102 are implanted within the capsularbag 20 in essentially the same way as the haptics of lens 32 so thatfibrosis of the rim 22 occurs about the haptics in the same manner asdescribed in connection with FIGS. 1-8. The anteriorly offset optic 104of the lens 100, on the other hand, protrudes through the anterioropening 26 in the capsular bag 20 and is situated anteriorly of the rimand between the rim and the iris 18 of the eye. There is sufficientspace between the rim and the iris to accommodate the optic of aproperly sized lens without the optic contacting the iris.

FIGS. 16-20 illustrate modified accommodating intraocular lensesaccording to the invention having means for fixating or anchoring thelens haptics in the capsular bag 20 to prevent the lenses from enteringthe vitreous cavity 21 of the eye in the event that the posteriorcapsule 24 becomes torn or a posterior capsulotomy must be performed onthe posterior capsule because it becomes hazy. Except as noted below,the modified intraocular lenses of FIGS. 16-20 are identical to the lens32 of FIGS. 1-8 and are implanted in the capsular bag 20 of the eye 10in the same manner as described in connection with FIGS. 1-8. Theintraocular lens 110 of FIGS. 16 and 17 is identical to lens 32 exceptthat the outer ends of the lens haptics 112 have raised shoulders 114.Fibrosis of the capsular rim 22 around the haptics 112 and theirshoulders 114 anchors or fixates the lens 110 in the capsular bag 20.The intraocular lens 116 of FIG. 18 is identical to lens 32 except thatflexible stalk-like knobs 118 extend diagonally from the outer ends ofthe lens plate haptics 120. The distance between the outer ends of thediametrically opposed knobs 118 is slightly larger than the distancebetween the outer ends of the lens haptics and slightly larger than thediameter of the capsular bag 20. The knobs are set wider than the widthof the lens body. These two features help to center the intraocular lenswithin the capsular bag so that the lens optic is centered immediatelybehind the circular capsulotomy 26 in the bag. Fibrosis of the capsularrim 22 around the haptics 120 and their knobs 118 fixes the lens 116 inthe capsular bag 20. The intraocular lens 122 of FIG. 19 is identical tolens 32 except that the outer ends of the lens haptics 124 have openings126. Fibrosis of the capsular rim 22 occurs around the haptics 124 andthrough their openings 126 to fixate the lens 122 in the capsular bag20. The intraocular lens 128 of FIG. 20 is similar to the lens 122 inthat the lens 128 has openings 130 in the outer ends of its haptics 132through which fibrosis of the capsular rim 22 occurs to fixate the lensin the capsular bag 20. Unlike the lens 122, however, the hapticopenings 130 are bounded along the outer ends of the haptics by springloops 134. The overall length of the lens 128, measured between thecenters of the spring loops 134 is made slightly greater than themaximum diameter of the capsular bag. The spring loops 134 press againstand are deformed inwardly slightly by the outer circumference of thecapsular bag to center the lens in the eye during fibrosis.

The modified intraocular lens 140 of FIG. 21 is identical to the lens 32of FIGS. 1-8 except that the lens 140 has centration nipples 142projecting endwise from the outer ends of the lens haptics 144 tocompensate for slight differences, from one patient to another, in thediameter of the human capsular bag 20. Thus, the diameter of thecapsular bag varies from about 11 mm in high myopes to about 9.5 mm inhigh hyperopes. The centration nipples 142 prevent differences in thedegree of flexing of the haptics 144 in capsular bags of differentdiameters. For example, in a hyperopic eye with a small capsular bag,the lens haptics would flex more with marked posterior vaulting of thelens by the fibrosed capsular rim compared to the minimal vaulting ofthe haptics which would occur in high myopes with relatively largecapsular bags. The nipples indent themselves into the outercircumference of the capsular bag to compensate for such differing bagdiameters and thereby center the lens in the bag.

The modified intraocular lens 150 illustrated in FIGS. 22-24 comprises alens body 152 proper identical to that of FIGS. 1-8 and springs 154 inthe form of U-shaped hoops constructed of biologically inert springmaterial. The ends of these springs are fixed to the anterior sides ofthe lens haptics 156 adjacent the haptic hinges 158 in such a way thatthe arched ends of the springs extend a small distance beyond the outerends of the haptics. The springs are stressed to normally lie relativelyclose to the anterior sides of the haptics. The lens body 152 isimplanted within the capsular bag 20 of the eye 10 in the same way asdescribed in connection with the lens 32 of FIGS. 1-8, and with theouter arched ends of the lens springs 154 lodged within the sulcus 19 ofthe eye between the iris 18 and the cornea 12. When the lens is in theposition of FIG. 23 which it occupies immediately after surgery as wellas after some degree of accommodation, the springs 154 lie relativelyclose to the anterior sides of the lens haptics 156. During posteriordisplacement of the lens to its distant vision position of FIG. 24 bythe posterior bias of the fibrosed capsular rim 22, the springs aredeflected anteriorly away from the lens haptics, as shown, therebycreating in the springs elastic strain energy forces which aid thestretched posterior capsule 24 and vitreous cavity pressure indisplacing the lens anteriorly during accommodation in response tocontraction of the ciliary muscle 28.

FIGS. 25-32 illustrate modified intraocular lenses according to theinvention having a lens body and separate lens fixation elements forpositioning the lenses in the capsular bag 20. Fibrosis of the capsularrim 22 occurs around these fixation elements in a manner which securelyfixes the elements within the bag. In some figures, the lens body isseparable from the fixation elements to permit removal of the lens fromand replacement of the lens in its original position in the eye. Inother figures, the lens body and fixation elements are secured againstseparation to prevent entrance of the lens body into the vitreouschamber in the event a tear develops in the posterior capsule 24 of thebag or a posterior capsulotomy is performed in the capsule.

The modified lens 160 of FIG. 25 includes a lens body 162 which isidentical, except as noted below, to that of lens 32 in FIGS. 1-8 andseparate fixation elements 164 at the outer ends of the lens haptics166. The fixation elements and haptics are interengaged in such a waythat the elements and haptics are capable of relative movementlengthwise of the haptics when the haptics flex during accommodation ofthe lens. The fixation elements 164 in FIG. 25 are generally U-shapedloops of biologically inert material having legs 168 which slide withinlongitudinal sockets 170 entering the outer ends of the haptics 166. Thehaptics 166 are somewhat shorter in length than those of the lens 32,and the overall length of the lens, measured between the outer archedends of the fixation loops 164, when their legs 168 abut the bottoms oftheir sockets 170, is less than the maximum diameter of the capsular bag20 when the ciliary muscle 28 is relaxed and greater than the diameterof the bag when the ciliary muscle is fully contracted foraccommodation. The lens 160 is implanted within the capsular bag 20 ofthe eye 10 with the fixation loops 164 and the outer ends of the haptics166 disposed between the anterior rim 22 and posterior capsule 24 of thecapsular bag 20. The outer arched ends of the loops are situated at theouter circumference of the bag.

Fibrosis of the capsular rim 22 occurs around the outer ends of the lenshaptics 166 and the exposed outer ends of the fixation loops 164 andthrough the spaces between the haptics and the loops in such a way thatthe loops are firmly fixed in the capsular bag, and the haptics formpockets 42 in the fibrose tissue F. The posterior bias of the fibrosedcapsular rim 22 urges the lens posteriorly to its distant visionposition when the ciliary muscle 28 is relaxed, thereby stretching theposterior capsule 24 rearwardly in the same manner as explained inconnection with FIGS. 1-8. When the ciliary muscle contracts duringaccommodation, the vitreous cavity pressure increases and the capsularrim 22 relaxes, thereby permitting the stretched posterior capsule andthe vitreous cavity pressure to push the lens body 162 forwardly towardits near vision position, again in the same manner as explained inconnection with FIGS. 1-8. Contraction of the capsular bag in responseto contraction of the ciliary muscle during accommodation displacementexerts inward forces on the fixation loops 164. These inward forces urgethe loops inwardly in their haptic sockets 170 until the loops abut thebottoms of the sockets. The inward forces exerted on the loops thenproduce an anterior buckling moment on the lens body 162 which aidsaccommodation of the lens by the posterior capsule. During thisaccommodation, the lens haptics 166 flex posteriorly relative to thelens optic 172 and slide inwardly in their fibrose pockets 42 and alongthe legs 168 of the fixation loops 164, the movement being aided byhinges 38.

The fixation loops have holes 174 in their outer arched ends throughwhich a suture 176 may be passed and tied to retain the loops and lensbody in assembled relation during implantation of the lens in thecapsular bag. This suture is removed at the conclusion of the surgery.Holes 174 may also be utilized to position the lens in the capsular bagduring surgery. The lens haptics 166 are separable from and reengageablewith the fixation loops 164. This permits the lens body 162 to beremoved from the eye any time after surgery for correction orreplacement of the lens optic 172 and then replaced in its originalposition in the eye.

The modified intraocular lens 180 of FIG. 26 is similar to that of FIG.25 except for the following differences. First, the haptics 182 of lens180 are substantially the same length as the haptics of lens 32 and havecutouts 184 in their outer ends. The legs 188 of the fixation loops 186slide in sockets 190 which enter the bottom edges of the cutouts 184.When the lens is implanted within the capsular bag 20, the tongue-likehaptic portions at opposite sides of the haptic cutouts 184 and theouter arched ends of the fixation loops 186 are situated within theouter circumference of the bag. As with the lens of FIG. 25, fibrosis ofthe capsular rim 22 occurs around the haptics 182 and fixation loops 186and through the spaces between the haptics and loops so as to firmly fixthe loops in the capsular bag and form pockets within which the hapticsslide when they flex during accommodation of the lens. Secondly, thelegs 188 of the fixation loops 186 and their sockets 190 in the lenshaptics 182 are tapered to facilitate free relative movement of theloops and haptics when the haptics flex during accommodation. Thirdly,the fixation loops have fixation nipples 192 at their outer arched endswhich indent into the outer circumference of the capsular bag 20 toretain the lens against movement relative to the bag during fibrosis.

FIG. 27 illustrates a modified intraocular lens 196 like the lens 180illustrated in FIG. 26 except that the legs 198 of the fixation loops200 and the haptic sockets 202 which receive these legs have coactingshoulders 204, 206. These shoulders permit limited relative movement ofthe lens body 208 and loops when the haptics 210 flex during lensaccommodation, but secure the lens body and loops against completeseparation so as to prevent the lens body from entering the vitreouschamber 21 if a tear occurs or a capsulotomy is performed in, theposterior capsule 24. Another difference between the lens 196 and thelens 180 resides in the fact that the hinges 212 connecting the innerends of the haptics 210 to the lens optic 214 extend across only anintermediate portion of the haptic width. The remaining lateral portionsof the inner haptic ends beyond the ends of the hinges are separatedfrom the optic by arcuate slots 216 centered on the axis of the optic.These separations of the haptics from the optic permit the optic to movefreely into and from the anterior opening or capsulotomy 26 in thecapsular bag 20 without interference with the capsular rim 22 duringlens accommodation. The generally triangular haptic portions adjacentthe slots 216 prevent the rim 22 of the capsular bag 20 from fibrosingbetween the lens optic 214 and the inner ends of the lens haptics 210and thereby restricting endwise movement of the haptics in theirfibrosed pockets 42.

The modified lens 220 of FIG. 28 includes a lens body 222 and separatefixation elements 224 at the outer ends of the lens haptics 226. Theinner ends of the haptics are convexly curved and disposed in generallytangential relation to diametrically opposite sides of the lens optic228 so as to provide relatively large clearance spaces 230 between theoptic and the inner haptic ends. The haptics and optic are joined alongtheir tangential portions by flexible hinges 232. The fixation elements224 are generally cruciform shaped pins having inner journals 234 whichslide and rotate within bearing bores 236 entering the bottom edges ofcutouts 238 in the outer ends of the haptics 226. These fixation pinshave holes 240 between their ends, outer cross arms 242, and nipples 244at their outer ends. The length of the lens 220 measured between theouter ends of its haptics 226 and fixation pins 224 approximates themaximum inner diameter of the capsular bag 20 when the ciliary muscle isrelaxed. The fixation pin journals 234 and their bores 236 have coactingshoulders 246, 248 which permit limited relative movement of the lensbody and fixation pins when the haptics flex during accommodation butsecure the body and fixation pins against complete separation, for thesame reasons as explained above in connection with FIG. 27. If desired,the shoulders 246, 248 may be eliminated to permit separation of thefixation pins and lens body for the same reasons as explained inconnection with FIG. 26. If the shoulders are eliminated, a removablesuture may be threaded through the fixation pin holes 240 and tied tohold the fixation pins and lens body in assembled relation duringimplantation of the lens, as explained in connection with FIG. 25. Theholes may also be used to position the lens in the capsular bag duringimplantation of the lens.

When the lens 220 is implanted within the capsular bag 20 of the eye 10,the outer ends of the lens haptics 226 and the fixation pins 224 aredisposed between the capsular rim 22 and posterior capsule 24 of the bagin much the same way as described in connection with FIGS. 25-27. Thenipples 244 indent the outer circumference of the bag to fix the lensagainst rotation circumferentially around the bag and center the lens inthe eye during fibrosis of the rim 22. Fibrosis of the capsular rimoccurs about the outer ends of the haptics and the fixation pins tofirmly fix the pins in the bag and form pockets in the fibrosed tissuereceiving the haptics. The lens body 222 is urged posteriorly to itsdistant vision position by the posterior bias of the capsular rim 22when the ciliary muscle 28 relaxes and anteriorly toward its near visionposition during accommodation by the stretched posterior capsule 24 andincrease in vitreous cavity pressure when the ciliary muscle contracts,all in essentially the same way as explained earlier in connection withFIGS. 25-27. During anterior accommodation of the lens, contraction ofthe capsular bag 20 in response to contraction of the ciliary muscleexerts inward forces on the outer ends of the haptics 226 which producean anterior buckling moment on the lens body 222 that aids lensaccommodation by the posterior capsule. The cross arms 242 of thefixation pins 224 are enveloped by the fibrosed tissue F during fibrosisof the rim 22 to provide pivots about which the pins can rotate duringbuckling of the lens body in the course of lens accommodation. Thespaces 230 between the inner ends of the haptics 226 and the optic 228accommodate movement of the optic into and from the opening 26 in thecapsular bag without interference with the surrounding capsular rim 22.

The modified intraocular lenses 260, 262 in FIGS. 29 and 30 areidentical to the lenses 180, 196, respectively, in FIGS. 26 and 27except that the fixation loops of the latter lenses are replaced inFIGS. 29 and 30, by fixation pins 264, 266 like those in FIG. 28.

The modified intraocular lenses 270, 272 in FIGS. 31 and 32 areidentical to the lens 32 of FIGS. 1-8 except that lens 270 has lateralspring arms 274 which extend from the haptic hinges 276 and lens 272 haslateral spring arms 278 which extend from the edges of the lens haptics280. The arms 274, 278 extend laterally from and longitudinally towardthe outer ends of the lens haptics in such a way that in their normalunstressed positions, the arms are disposed at acute angles relative tothe longitudinal axes of the lenses. The arms are sized in length sothat when the lenses are implanted within the capsular bag 20 of theeye, the outer ends of the arms press against the outer circumference ofthe bag and are thereby curled or compressed to the positionsillustrated in broken lines. The curl or compression in the armsdecreases when the capsular bag expands in response to relaxation of theciliary muscle during distant vision accommodation of the lens andincreases when bag contracts in response to contraction of the ciliarymuscle during near vision accommodation of the lens. Engagement of thearms with the capsular bag circumference acts to center the lenses inthe bag in a position wherein the lens optics 282, 284 are coaxiallyaligned with the anterior bag opening or capsulotomy. Fibrosis of thecapsular rim 22 occurs about the spring arms to fix the lenses withinthe capsular bag and about the lens haptics to form pockets in which thehaptics slide when they flex during accommodation of the lenses.

Referring to FIG. 32 and to FIGS. 4 to 8, projections such as thoseindicated at 286 in FIG. 32, may preferably be provided in variousembodiments of the invention to space the capsulorhexis from the opticwhen the capsulorhexis constricts from its configuration shown in FIGS.5 to 8. This spacing prevents the anterior capsular rim 22, with arelatively small capsular opening 26, from encroaching onto the opticduring fibrosis of capsular rim 22. As shown in FIG. 32, suchprojections 286 extend outwardly anteriorly from the plate hapticsurface, and are disposed about and spaced from the optic. Theprojections extend outwardly no farther than the outer extent of theoptic, typically to a height of about 1-1.5 mm. The projections may bein the form of continuous arcs (not shown) and may be inclined outwardlyrelative to the optic.

The modified accommodating intraocular lens 290 of FIG. 33 comprises acircular optic 292 and two pairs 294, 296 of curved, flexible haptics298, 300 extending from opposite edges of the optic. These haptics havethe form of relatively slender arms. At the outer ends of the hapticsare enlarged knobs 302. The two haptics 298 of each haptic pair 294, 296extend out from the optic 292 in mutually divergent relation and curveaway from one another toward their outer ends, as shown. The fourhaptics are disposed in symmetrical relation relative to a plane ofsymmetry containing the axis of the optic and passing midway between thetwo haptics of each haptic pair. The two haptics 298 are locateddiametrically opposite one another, and the two haptics 300 are locateddiametrically opposite one another. The diametrical distance measuredbetween the outer ends of the diametrically opposed haptics 298, 300 ismade slightly greater than the maximum diameter of capsular bag 20. Thelens 290 is implanted within the bag in much the same manner as theearlier embodiments of the invention and with the outer ends of the lenshaptics 298, 300 disposed between the anterior capsular rim 22 andposterior capsule 24 of the bag. The outer ends of the haptics pressresiliently against the outer circumference of the bag and flex or bendin such a way as to both accommodate bags of different diameter andcenter the optic 292 behind the anterior capsulotomy in the bag. Theanterior capsular rim 22 of the bag fibroses about the haptics to fixatethe lens in the bag. After fibrosis is complete, brain initiatedrelaxation and constriction of the ciliary muscle 28 of the eye iseffective to cause accommodation of the lens between near and distantvision positions in essentially the same manner as described earlier.During this accommodation, the lens buckles and the haptics flexanteriorly and posteriorly relative to the optic 292 in much the sameway as described earlier. Fibrosis of the capsular rim about the hapticknobs 302 fixates the lens in the capsular bag and against dislocationin the event a tear or capsulotomy is formed in the posterior capsule 24of the bag.

The modified accommodating intraocular lens 310 of FIG. 34 is similar tothe lens 290 of FIG. 33 and differs from the lens 290 only in thefollowing respects. The four haptics 312, 314 of the lens 310, ratherthan being slender curved arms like those of lens 290, are symmetricallytapered from relatively wide inner ends which are joined to the lensoptic 316 to relatively narrow outer ends. At the outer ends of thehaptics 312, 314 are enlarged knobs 318. At inner ends of the hapticsare grooves 320 which form flexible hinges 322 about which the hapticsare flexible anteriorly and posteriorly of the optic. The diametricaldistance between the outer ends of the diametrically opposed haptics312, 314 approximates or slightly exceeds the maximum diameter of thecapsular bag 20. The lens 310 is implanted within the bag, and fibrosisof the anterior capsular rim 22 of the bag occurs about the lens hapticsin the same way as described in connection with lens 290. After fibrosisis complete, brain initiated relaxation and constriction of the ciliarymuscle 28 of the eye cause accommodation of the lens in the same manneras described in connection with lens 290. Fibrosis of the capsular rimabout the haptic knobs 318 fixates the lens in the capsular bag andagainst dislocation in the event a tear or capsulotomy is formed in theposterior capsule 24 of the bag.

The accommodating plate haptic lenses described to to this point arereferred to herein as simple plate haptic lenses. These lenses areintended for use when the capsulorhexis procedure performed on the eyeis a properly performed continuous tear capsulotomy which provides ananterior annular capsular remnant or rim that remains intact andcircumferentially continuous throughout fibrosis and has a sufficientradial width to retain the lens in the proper position within thecapsular bag during and/or fibrosis. According to another of itsaspects, this invention provides modified accommodating intraocularlenses, illustrated in FIGS. 38-40 and 43-46 and referred to as platehaptic spring lenses, for use when the anterior capsular remnant or rimof the capsular bag is ruptured, that is cut or torn, or has too small aradial width to firmly retain the lens in proper position during and/orafter fibrosis.

As noted earlier, a ruptured capsular remnant or rim may occur indifferent ways. For example, continous tear circular capsulorhexis (FIG.35) involves tearing the anterior capsule of the natural lens along acircular tear line to form in the anterior capsule a circular opening orcapsulotomy 400 circumferentially surrounded by an annular remnant orrim 402 of the anterior capsule. Improper performance of thiscapsularhexis can easily create slits or tears 404 in the capsular rim.A beer can or can opener capsulorhexis (FIG. 36) involves piercing theanterior capsule of the natural lens at a multiplicity of closepositions 404 along a circular line and removing the circular portion ofthe anterior capsular rim within the pierced line to form an anteriorcapsulotomy 406 circumferentially surrounded by an annular rim 408.While this rim may be initially intact and circumferentially continuous,it has an inner scalloped edge 410 having stress-inducing regions thatrender the rim very prone to tearing radially, as shown at 411, duringsurgery or subsequent fibrosis. An envelope capsulorhexis (FIG. 37)involves slitting the anterior capsule of the natural lens along ahorizontal line 412, then along vertical lines 414 extending upwardlyfrom and intersecting the horizontal slit, and then tearing the anteriorcapsule along a tear line 416 which arches upwardly from the upper endof the vertical slit and then extends vertically downward to join thesecond vertical cut. This capsulorhexis produces an anterior capsulotomy418 bounded by a capsular remnant 420 which is slit at 412 and hence isinherently ruptured.

A ruptured anterior capsular remnant or rim may preclude utilization ofa dimple plate haptic lens of the invention for the following reasons. Aruptured rim may not firmly retain the lens haptics in the sulcus of thecapsular bag during fibrosis. This renders the lens prone todecentration and/or dislocation, such as dislocation into the vitreouscavity if the posterior capsule tears or becomes cloudy over a period oftime and is cut with a laser to provide a capsulotomy in the posteriorcapsule. A ruptured capsular rim may be incapable of assuming the tauttrampoline-like condition of an intact capsular rim. As a consequence, aruptured capsular rim may be incapable of effecting full posteriordeflection of a plate haptic lens to a distant viewing position againstthe posterior capsule during and after fibrosis. A ruptured capsular rimmay also permit anterior deflection of the lens during fibrosis. Ineither case, since the power of an intraocular lens is selected for eachindividual patient and may be dependent upon their spectacle power andsince good vision without glasses requires the lens optic to be situatedat precisely the correct distance from the retina throughout the rangeof accommodation, a simple plate haptic lens of the invention may not beacceptable for use with a ruptured anterior capsular remnant or rim.

FIGS. 38-40 illustrate an accommodating plate haptic spring intraocularlens 420 of the invention for use with a ruptured anterior capsularremnant or rim, such as any one of those illustrated in FIGS. 35-37.This plate haptic spring lens has a lens body 422 proper similar to thatof the plate haptic lens 32 in FIGS. 1-8 and springs 424 at the ends ofthe body. The lens body 422 includes a central optic 426 and flexibleplate haptics 428 extending outward from diametrically opposite sides ofthe optic. These haptics are joined to the optic by hinges 429 formed bygrooves in the anterior side of the lens. The springs 424 are resilientloops which are staked at one end to the ends of the haptics 428 atopposite sides of the longitudinal centerline of the body. These springloops bow outwardly lengthwise of the lens body from their staked endsto their centers and then turn back toward the lens body from theircenters to their free ends. The ends of the haptics 428 have recesses430 over which the spring loops extend in such a way that the loops andthe edges of the recesses form openings 432 therebetween. The ends ofthe spring loops have holes 433 to receive instruments for positioningthe lens in the eye.

The plate haptic spring lens 420 is implanted within the capsular bag 20of the eye in the same manner as described earlier in connection withthe simple plate haptic lenses of the invention. That is to say, thelens 420 is implanted within the eye while its ciliary muscle 28 isparalyzed in its relaxed state, and the capsular bag is therebystretched to its maximum diameter (9-11 mm). The overall length of thelens body 422 measured between the ends of the lens haptics 428 ateither side of the haptic recesses 430 substantially equals the innerdiameter of the stretched capsular bag. The overall length of the lensmeasured between the outer edges of the spring loops 424 at theircenters when the loops are in their normal unstressed state is slightlygreater than this inner diameter of the stretched capsular bag. Forexample, if the inner diameter of the stretched capsular bag is in therange 10-10.6 mm, the lens body 422 will have an overall length of10-10.6 mm measured between the outer ends of the lens haptics, and theoverall length of the lens measured between the centers of theunstressed spring loops will be in the range of 11-12.5 mm.

FIGS. 39 and 40 illustrate the plate haptic spring lens 420 implanted ina capsular bag 20 which is stretched by relaxation of the ciliary muscle28 and has a torn anterior capsular rim 22i such as might result from animproperly performed continuous tear circular capsulorhexis. Because therim is torn, the lens body 422 will not fit as snugly in the stretchedbag as it would if the capsular rim were an intact rim free of tears.The haptic spring loops 424, however, press outward against the wall ofthe capsular bag sulcus about the rim of the bag to fixate the lens inthe bag during fibrosis following surgery. Fibrosis of the torn capsularrim 22 occurs about the outer ends of the plate haptics 428, about thespring loops 424, and through the openings 432 between the loops and theends of the haptics in such a way as to effect fusion of the torn rim,or more precisely the remnants of the torn rim, to the posterior capsule24 of the capsular bag. The outer ends of the haptics and the springloops are thereby shrink-wrapped by fibrosis in somewhat the same manneras explained earlier in connection with the simple plate haptic lensesof the invention. Even though the torn capsular rim 22 may be incapableof stretching to the taut trampoline condition discussed earlier whenthe ciliary muscle is relaxed, this shrink-wrapping of the lens duringfibrosis of the torn rim will firmly fixate the lens in the capsular bagand should cause some posterior deflection of the lens against theelastic posterior capsule 24. Accordingly, brain-induced constrictionand relaxation of the ciliary muscle 28 after fibrosis of the torncapsular rim is complete should effect accommodation of the plate hapticspring lens in much the same way, but possibly not with the same amountof accommodation, as the simple plate haptic lens with an intactnon-ruptured capsular rim.

While the plate haptic spring lens 420 is designed for use with aruptured anterior capsular remnant or rim, it can also be utilized withan intact rim. A plate haptic spring lens also compensates for improperlens placement in the eye with one end of the lens situated in thecapsular bag and the other end of the lens situated in the ciliarysulcus of the eye since the spring loops will expand outwardly to engageboth the inner edge of the bag and the wall of the ciliary sulcus. Inthis regard, an advantage of the plate haptic spring lenses of theinvention over the simple plate haptic lenses resides in the fact thatthe spring lenses eliminate the need to have on hand in the operatingroom both a simple plate haptic lens for use with an intact capsular rimand a plate haptic spring lens as a backup for the plate haptic lens inthe event the rim is ruptured during surgery.

Another advantage of the haptic spring lens 420 resides in the fact thatit permits the lens to have a larger optic than a simple plate hapticlens whose optic diameters will normally be within the range of 4-7 mm.Thus, since the haptic spring lens relies on the spring loops 424 ratherthan on the capsular remnant or rim 22 to retain the lens in positionduring fibrosis, the lens may be used with a capsular remnant or rim ofsmaller radial width and hence larger capsulotomy diameter than thoserequired for use of the simple plate haptic accommodating lenses. Thelarger capsulotomy, of course, permits a larger optic diameter in therange of 7-9 mm which offers certain ophthalmological benefits.

The large capsulotomy necessary to accommodate a large optic springaccommodating lens may be formed during the original surgery by aplanned large continuous tear circular capsulorhexis, a beer cancapsulorhexis of the desired large diameter, a planned envelopecapsulotomy or the cutting of radial slits into a small continuous tearcapsulotomy during surgery after implanting the spring accommodatinglens. According to another of its aspects, the invention provides amethod whereby the desired large anterior capsulotomy may be formedafter the original surgery following completion of fibrosis. This methodinvolves slitting an annular capsular rim radially with a laser afterfibrosis is complete into a number of flap-like remnants 434 (FIG. 41)which are easily displaced by the lens during accommodation to enlargethe capsulotomy sufficiently to permit the lens optic to pass throughthe capsulotomy. Alternatively, the capsulotomy may be enlarged bycutting the capsular rim with a laser circumferentially along a circularline 436 (FIG. 42) concentric with and radially outwardly of theoriginal edge of the capsulotomy to enlarge the latter.

The modified plate haptic spring lens 500 of FIG. 43 is identical to thelens 420 just described except that the haptics 502 of the modifiedlens, rather than being hinged to the lens optic 504, are resilientlyflexible throughout their length like those of the plate haptic lens inFIG. 9. FIG. 44 illustrates a further modified plate haptic spring lens600 according to the invention which is identical to the lens 420 exceptthat the spring loops 602 of the modified lens are formed integrallywith the lens haptics 604. The modified lens 700 and 800 of FIGS. 45 and46 are identical to the lens 600 except that the modified lenses have apair of spring loops at each end. The spring loops 702 of lens 700 havecommon base portions 704 integrally joined to the ends of the lenshaptics 706 along the longitudinal centerline of the lens and free endswhich curve outwardly from the base portions both endwise and laterallyof the lens. The spring loops 802 of lens 800 have base portions 804integrally joined to the ends of the lens haptics 806 along thelongitudinal edges of the haptics and opposite free ends which curveinwardly toward one another laterally of the lens.

Thus there has been shown and described a novel accommodatingintraocular lens which fulfills all the objects and advantages soughttherefor. Many changes, modifications, variations and other uses andapplications of the subject invention will, however, become apparent tothose skilled in the art after considering this specification togetherwith the accompanying drawings and claims. All such changes,modifications, variations and other uses and applications which do notdepart from the spirit and scope of the invention are deemed to becovered by the invention which is limited only by the claims whichfollow.

What is claimed is:
 1. An accommodating intraocular lens to be implanted within a human eye having a natural capsular bag attached about its perimeter to the ciliary muscle of the eye and from which the natural lens matrix has been removed, the bag including an elastic posterior capsule urged anteriorly by vitreous pressure in the eye and an anterior capsulotomy circumferentially surrounded by a capsular remnant having epithelial cells on its posterior side which cause fusion of the remnant to the posterior capsule by fibrosis during a certain postoperative period following implantation of the lens in the eye, said intraocular lens comprising:a lens body having normally anterior and posterior sides and including an optic and plate haptics which extend from two diametrically opposite edges of said optic and have inner ends joined to the optic and opposite outer ends which are movable anteriorly and posteriorly relative to said optic, wherein said lens body includes hinges joining the inner ends of said haptics to said optic about which said haptics are pivotally movable anteriorly and posteriorly relative to said optic, wherein said lens body contains grooves in at least one of said body sides along the inner ends of said haptics forming flexible, reduced thickness portions of the lens body which constitute said hinges, and wherein said intraocular lens is sized to be implanted within said capsular bag when the ciliary muscle is paralyzed in its relaxed state and in a position wherein the outer ends of said haptics are disposed between said capsular remnant and the outer perimeter of said posterior capsule and said optic is aligned with said anterior capsulotomy to permit fibrosis about the haptics of the implanted lens during said post-operative period in such a way that after fibrosis is complete, relaxation of the ciliary muscle effects posterior movement of the implanted lens and constriction of the ciliary muscle effects anterior accommodation of the implanted lens.
 2. An accommodating intraocular lens comprising:a lens body having normally anterior and posterior sides and including an optic, and plate haptics extending from opposite edges of said optic and having inner ends adjacent said optic and opposite outer ends, wherein said intraocular lens includes hinge means pivotally joining said inner haptic ends to said optic for pivotal movement of said haptics about said hinge means anteriorly and posteriorly relative to said optic, wherein said hinge means comprise flexible hinge portions of said lens body, and wherein said hinge portions comprise reduced thickness portions of said lens body formed by grooves in at least one of said body sides.
 3. An accommodating intraocular lens to be implanted within a human eye having a natural capsular bag attached about its perimeter to the ciliary muscle of the eye and from which the natural lens matrix has been removed, the bag including an elastic posterior capsule urged anteriorly by vitreous pressure in the eye and an anterior capsulotomy circumferentially surrounded by a capsular remnant having epithelial cells on its posterior side which cause fusion of the remnant to the posterior capsule by fibrosis during a certain postoperative period following implantation of the lens in the eye, said intraocular lens comprising:a lens body having normally anterior and posterior sides and including an optic and plate haptics which extend from two diametrically opposite edges of said optic and have inner ends joined to the optic and opposite outer ends which are movable anteriorly and posteriorly relative to said optic, wherein said intraocular lens includes springs at the outer ends of said haptics having normal unstressed positions wherein said springs extend beyond their adjacent outer haptic ends in the endwise directions of the haptics for resilient engagement with the perimeter of said bag to firmly position the lens in the bag during fibrosis and prevent dislocation of the lens in the bag if said capsular remnant is torn, slit, or otherwise ruptured during surgery or fibrosis, wherein said springs comprise spring loops having base ends fixed to said haptics and opposite free ends, and each spring loop curves outwardly from the outer end of its respective haptic in the endwise direction of the haptic and laterally of the haptic from the base end to a certain position along the respective loop and then back toward the outer end of the respective haptic from said certain position to said free end of the respective haptic and wherein said intraocular lens is sized to be implanted within said capsular bag when the ciliary muscle is paralyzed in its relaxed state and in a position wherein the outer ends of said haptics are disposed between said capsular remnant and the outer perimeter of said posterior capsule and said optic is aligned with said anterior capsulotomy to permit fibrosis about the haptics of the implanted lens during said postoperative period in such a way that after fibrosis is complete, relaxation of the ciliary muscle effects posterior movement of the implanted lens and constriction of the ciliary muscle effects anterior accommodation of the implanted lens.
 4. An accommodating intraocular lens to be implanted within a human eye having a natural capsular bag attached about its perimeter to the ciliary muscle of the eye and from which the natural lens matrix has been removed, the bag including an elastic posterior capsule urged anteriorly by vitreous pressure in the eye and an anterior capsulotomy circumferentially surrounded by a capsular remnant having epithelial cells on its posterior side which cause fusion of the remnant to the posterior capsule by fibrosis during a certain postoperative period following implantation of the lens in the eye, said intraocular lens comprising:a lens body having normally anterior and posterior sides and including an optic and plate haptics which extend from two diametrically opposite edges of said optic and have inner ends joined to the optic and opposite outer ends which are movable anteriorly and posteriorly relative to said optic, wherein said intraocular lens includes springs at the outer ends of said haptics having normal unstressed positions wherein said springs extend beyond their adjacent outer haptic ends in the endwise directions of the haptics for resilient engagement with the perimeter of said bag to firmly position the lens in the bag during fibrosis and prevent dislocation of the lens in the bag if said capsular remnant is torn, slit, or otherwise ruptured during surgery or fibrosis, wherein said springs comprise a single spring loop on the outer end of each haptic having a base end fixed to the respective haptic adjacent one longitudinal edge of the haptic and opposite free end, the base ends of the haptics are situated adjacent opposite longitudinal edges of the haptics, and each spring loop curves outwardly from the outer end of its respective haptic in the endwise direction of the haptic and laterally of the haptic from its base end to a certain position along the respective loop and then back toward the outer end of the respective haptic from said certain position to said free end of the respective haptic and wherein said intraocular lens is sized to be implanted within said capsular bag when the ciliary muscle is paralyzed in its relaxed state and in a position wherein the outer ends of said haptics are disposed between said capsular remnant and the outer perimeter of said posterior capsule and said optic is aligned with said anterior capsulotomy to permit fibrosis about the haptics of the implanted lens during said postoperative period in such a way that after fibrosis is complete, relaxation of the ciliary muscle effects posterior movement of the implanted lens and constriction of the ciliary muscle effects anterior accommodation of the implanted lens.
 5. An accommodating intraocular lens comprising:a lens body having normally anterior and posterior sides and including an optic, and plate haptics extending from opposite edges of said optic and having inner ends adjacent said optic and opposite outer ends, wherein said intraocular lens includes springs at the outer ends of said haptics having normal unstressed positions wherein said springs extend beyond their adjacent outer haptic ends in the endwise directions of the haptics for resilient engagement with the perimeter of said bag to firmly position the lens in the bag during fibrosis and prevent dislocation of the lens in the bag if said capsular remnant is torn, slit, or otherwise ruptured during surgery or fibrosis, wherein said springs comprise spring loops having base ends fixed to said haptics and opposite free ends, and each spring loop curves outwardly from the outer end of its respective haptic in the endwise direction of the haptic and laterally of the haptic from the base end to a certain position along the respective loop and then back toward the outer end of the respective haptic from said certain position to said free end of the respective haptic, and wherein said intraocular lens includes hinge means pivotally joining said inner haptic ends to said optic for pivotal movement of said haptics about said hinge means anteriorly and posteriorly relative to said optic such that when said intraocular lens is fixed within a capsular bag of the eye between a posterior capsule of the capsular bag and a remnant of an anterior capsule of the capsular bag, said lens deflects anteriorly when the eye focuses on near objects and said lens deflects posteriorly when the eye focuses on distant objects.
 6. An accommodating intraocular lens comprising:a lens body having normally anterior and posterior sides and including an optic, and plate haptics extending from opposite edges of said optic and having inner ends adjacent said optic and opposite outer ends, wherein said intraocular lens includes springs at the outer ends of said haptics having normal unstressed positions wherein said springs extend beyond their adjacent outer haptic ends in the endwise directions of the haptics for resilient engagement with the perimeter of said bag to firmly position the lens in the bag during fibrosis and prevent dislocation of the lens in the bag if said capsular remnant is torn, slit, or otherwise ruptured during surgery or fibrosis, wherein said springs comprise a single spring loop on the outer end of each haptic having a base end fixed to the respective haptic adjacent one longitudinal edge of the haptic, and an opposite free end, wherein the base ends of the springs are situated adjacent opposite longitudinal edges of the haptics, wherein each spring loop curves outwardly from the outer end of its respective haptic in the endwise direction of the haptic and laterally of the haptic from its base end to a certain position along the respective loop and then back toward the outer end of the respective haptic from said certain position to said free end of the respective haptic, and wherein said intraocular lens includes hinge means pivotally joining said inner haptic ends to said optic for pivotal movement of said haptics about said hinge means anteriorly and posteriorly relative to said optic such that when said intraocular lens is fixed within a capsular bag of the eye between a posterior capsule of the capsular bag and a remnant of an anterior capsule of the capsular bag, said lens deflects anteriorly when the eye focuses on near objects and said lens deflects posteriorly when the eye focuses on distant objects.
 7. An accommodating intraocular lens adapted to be implanted within a human eye having a natural capsular bag attached about its perimeter to the ciliary muscle of the eye and from which the natural lens matrix has been removed, the bag including an elastic posterior capsule urged anteriorly by vitreous pressure and an anterior capsulotomy circumferentially surrounded by a capsular remnant fused by fibrose tissue to the posterior capsule, said lens comprising:an intraocular lens having normally anterior and posterior sides and including a central optic, and haptics extending from opposite edges of the optic and having inner ends joined to the optic and opposite outer ends movable anteriorly and posteriorly relative to said optic, wherein said lens includes hinges joining the inner ends of said haptics to said optic and about which said haptics are pivotally movable anteriorly and posteriorly relative to said optic, wherein said lens contains grooves in one of said lens sides along the inner ends of said haptics forming flexible, reduced thickness portions of the lens which constitute said hinges, and wherein said intraocular lens is adapted to be situated within said capsular bag in a position wherein said optic is aligned with said capsulotomy and the outer ends of said haptics are disposed between said anterior capsule rim and the outer perimeter of said posterior capsule and confined within pockets in the fibrose tissue in a manner such that relaxation of the ciliary muscle effects posterior deflection of the lens and constriction of the ciliary muscle effects anterior accommodation of the lens.
 8. An accommodating intraocular lens for insertion through an opening formed by capsulorhexis in an anterior capsule of a capsular bag of an eye for fixation adjacent to a posterior capsule of the capsular bag comprising:a central optic portion having an anterior surface and a posterior surface; and a plurality of extended portions extending radially from the central optic portion, each extended portion having a proximate end connected to the central optic portion and a distal end remote from the proximate end, each extended portion adapted to permit the lens to fit within the opening formed in the anterior capsule and to permit fixation of the intraocular lens, said extended portions adapted to rearwardly deflect the central optic portion against the posterior capsule under ciliary muscle relaxation, to forwardly deflect the central optic portion under ciliary muscle constriction, and to bias the central optic portion against the posterior capsule during a substantial portion of its movement, resulting in consistent accommodation of the implanted lens with said restriction and relaxation of the ciliary muscle. 